Magnetic data transducers are used to transmit data in the form of magnetic pulses. Such transducers (heads) generally comprise a coil that surrounds a magnetically permeable pole structure.
Bi-directional, time varying data transmission currents applied to the coil result in the transmission of corresponding bi-directional, time varying magnetic pulses. In a magnetic transmission system, the pulses are generally conveyed through an appropriate medium to a remote receiver. In a data storage device, such pulses generally operate to magnetically orient a recording medium such as a disc.
It has been observed that at the conclusion of the application of a sequence of data transmission currents, the magnetically permeable pole of a transducer can exhibit a residual magnetism. That is, magnetic domains within the pole are not substantially randomly arrayed, but are more or less commonly aligned along a particular axial direction.
Such residual magnetism will tend to have a natural decay life and return to the desired net random alignment over time. However, during this decay interval the aligned magnetism of the pole can adversely affect operation of the transducer by introducing noise in subsequent transmissions. When the transducer is used to write data to a medium, such magnetization can undesirably erase data previously written to the medium as the medium moves adjacent the transducer.
While various approaches have been proposed in the art to address residual magnetism in a transducer, there nevertheless remains a continued need for improvements in the art, and it is to such improvements that the present invention is directed.